A Birthday Party Isn't a Real Party Unless You Invite Oguri Shun
by Draconian Scribe
Summary: It's the first birthday they've celebrated since getting back together, and Gin-san decides to invite a few guests to make things extra special. Post-canon. GinTaka and implied OkiKagu. WARNING: MATURE AUDIENCES ONLY!


**AUTHOR'S NOTE (1):**

 **THIS IS YOUR LAST CHANCE TO TURN BACK AND SAVE YOURSELF. YOU HAVE BEEN WARNED.**

 **This story takes place in the same universe as Aeneid's "Of Public Sector and Golden Sukonbu," which is not a prerequisite, but you are highly encouraged to read at your own peril. Special shoutouts to dearfriendicanfly for inspiring the line about Gin-san and the candles, silverbluewords for reading through this on such short notice (and still agreeing to work with me), and last but not least, my beloved partner in crime, Aeneid, for being as disgusting as I am.**

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A BIRTHDAY PARTY ISN'T A REAL PARTY UNLESS YOU INVITE OGURI SHUN

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 _HAPI BAA HANII_

 _Make a wish and blow my dick_

 _I love you-r asshole_

"What the fuck?"

Shinsuke did _not_ get dragged—yes, physically _dragged!_ —out of bed in the middle of the night for this. His hands and feet may be bound, but that didn't stop him from ripping the crumpled sheet of paper, which turned out to be the back of yet another overdue notice about the rent, into pieces and grinding them into the dirt.

 _Ugh,_ this place was so filthy. The cold clamminess of the forest floor was seeping through his yukata and smearing it with grass stains. Twigs poked and scratched at him in every direction as he struggled to roll into a seated position. The shadows of several large, tattered stuffed animals peeked out from behind the trees and bushes, watching him with their dead, plastic eyes. What appeared to be their leader, a hulking purple bear with patches of fur missing and bits of stuffing dangling out of its missing eye, was sitting next to a cake in the shape of a phallus, its face frozen in a manic smile that glinted ominously in the feeble candlelight. Granted, the candles were already half-melted from the last time Gintoki forgot to pay the electric bill, but fortunately enough, he could still see. Or perhaps, _un_ fortunately, as his one eye fell upon the nearby flower vase and the pudgy caterpillar attempting to wriggle its way out of the mass of weeds that had been shoved into it.

He needed to escape. Quickly, before—

"Leaving already?" the hate of his life drawled from above, picking his nose and flicking the boogers at Shinsuke's increasingly reddening face.

"Let me go so I can strangle you," Shinsuke snarled.

"Wow. I should write you more erotic haikus if it gets you this hot and bothered—"

"What part of that was erotic? Half of it wasn't even in proper Japanese! You're still as illiterate as ever—"

"Hmm. Must be the cake then."

"I don't even _like_ cake!"

"You sure like my dick though. Its beauty tames your inner beast and all that," Gintoki snorted, chortling at his own joke.

"I'll show you 'inner beast,'" Shinsuke gritted through his teeth, abandoning all sense of dignity and attempting to gnaw his way through the ropes.

"So eager!" Gintoki cooed. "Please, don't let me stop you. I'm quite enjoying the view. In fact, I might even start touching myself right now—"

Shinsuke regretted many things about his life. His relationship with his parents, Sensei, Gintoki, the war, the past ten years, Gintoki, not spending more time with his friends, committing too many crimes to be sponsored by Yakult, but mostly Gintoki.

"You are literally the most disgusting person I have ever met," he declared, with feeling. "Don't come near me, you sadistic _fuck—"_

The bastard actually had the gall to look offended. "You wound me," Gintoki simpered, placing his hand on his heart in an exaggerated swooning motion. "Even after all the effort Gin-san put into treating you like a princess and carrying you out bridal style on your special day—"

 _"Bridal—_ WHO THE HELL DO YOU THINK I AM? You _kidnapped_ me! Gagged me! Blindfolded me! _Threw_ me over your shoulder and onto the fucking ground! You ruined my yukata! You ruined my entire fucking _life!"_

Gintoki fell silent. Suddenly, Shinsuke wondered if he'd gone too far. But it wasn't his fault! Gintoki was just so – so _vexing!_ He always knew exactly what to say to get Shinsuke all riled up, and he _hated_ it, he hated that Gintoki knew him so well.

But there was one thing he hated more.

Gintoki took a step towards him, his face unreadable, and Shinsuke swallowed guiltily, afraid he'd ruined their night. Although technically, Gintoki had already ruined their night. But _still._ The cruel jokes, the sexual harassment, the vulgar habits, even the explosive fights he could live with. What he couldn't live with was Gintoki's sadness.

To his relief, Gintoki's gaze softened and he now wore an expression of contrition. "You're right. I'm sorry," he said, kneeling down and untying Shinsuke's hands.

"Um, good," Shinsuke replied awkwardly, rubbing the welts on his wrists and trying to ignore the feeling of Gintoki's fingertips brushing against his skin. "So—"

"I shouldn't have blindfolded you. You're already half-blind."

He made a lunge for Gintoki's neck, forgetting that his legs were still bound, and toppled over face-first into the dirt with a high-pitched shriek.

"I know, I know, I'm such an insensitive bastard," Gintoki prattled on. "Just because I can still see out of both of my eyes, I forget about those less fortunate than me. But don't you worry your tiny little heart! Gin-san is exceedingly selfless and understanding. I know that it's hard for you to see my devotion when you're blinded by lust and also actually blinded, but I'll spend the next ten years making it up to you—"

"GINTOKIIIIII," he roared, scrabbling upright. "WHEN I GET MY HANDS ON YOU—"

 _"Yes,_ I love it when you talk dirty to me—"

This time, when he fell to the ground, he managed to take Gintoki down with him.

They rolled and wrestled for dominance, the world becoming a blur of wet leaves, pointy sticks, an _especially_ pointy stick rubbing up against his ass, breathy insults, and the salty-sweet tang of Gintoki's blood and sweat when he bit him in retaliation. Gintoki let out a satisfying yelp of shock and pinned his bound legs down with one hand, his eyes dark and promising retribution.

Shinsuke tumbled onto his back, the top of his head brushing against something soft and sticky. He licked his lips and smirked, knowing that Gintoki's gaze would be riveted on his tongue. He waited for Gintoki to lean forward, then smashed the crude, cock-shaped cake right into his face.

A muffled squawk, along with crumbly chunks of cake, came spraying out of his open mouth. The testes had somehow ended up on Gintoki's forehead, slowly sliding down the side of his face and smearing a sluggish trail of peach-coloured cream in its wake. The only sound to break the resulting silence was the cake's 'kintama' dropping to the ground with a sad splat.

A loud snort ripped up Shinsuke's nose. His entire body trembled and shook as tiny giggles squeaked past his lips. His eyes watered and he doubled over, clutching his chest as he erupted into howling peals of laughter. He squeezed his eye shut, gasping for air. Even then, he could still see Gintoki's face, speechless and splattered in the destruction of his own disgusting creation.

He lost track of how long it took him to finally sit up and wipe the tears of mirth from his eye, sniffling from a few lingering tremors. For some reason, Gintoki was still staring at him, his mouth slightly parted and his eyes looking oddly glazed. _Glazed. Pfft._ Shit, his gut stung. When was the last time he'd laughed this hard? He honestly couldn't remember. But it probably had something to do with this idiot sitting in front of him.

He scooted closer to Gintoki and curiously lapped up a few dollops of cream stuck to the underside of his jaw. He hummed. "Not bad. A bit sweet though."

Suddenly, all he could taste was sweetness as Gintoki grabbed his face and shoved his tongue into his mouth. Bits of cake slid in past his lips and were dragged and smeared in a sticky mess along his tongue. Shinsuke moaned and ran his hands through Gintoki's unruly, frosting-covered hair, then down the hard planes of his chest, leaving streaks of icing as he went. Gintoki's hands had long since wandered elsewhere, one hand cupping Shinsuke's ass and the other slowly lifting up the folds of his yukata and stroking every exposed centimetre of his thighs. Shinsuke tilted his hips to encourage him, letting out a gasp when Gintoki slipped his hand into his fundoshi and began circling his entrance with the tip of his finger. Gintoki took advantage of the opportunity to latch onto his neck and suck at his pulse, nipping him slightly with his teeth and smearing the surrounding skin with frosting. The material he was wearing suddenly felt too tight, chafing against his skin and his trapped dick. Very lightly, Gintoki brushed his finger over Shinsuke's opening, causing a loud growl to tear up the back of his throat.

He yanked Gintoki's hair and raked his nails down his scalp, hissing in his ear, "Untie my legs. _Right. Fucking. Now."_

He felt a rough tug at his feet indicating that Gintoki had, for once, complied without any additional commentary. He kicked off his flimsy undergarment, pretending not to notice Gintoki's hand sneaking across the grass and stuffing it somewhere under his kimono. Gintoki was irredeemably depraved and he had bigger things to worry about. _Much_ bigger. So instead, Shinsuke proceeded to _throw_ himself at the cause of all his pent-up frustration, clambering onto his lap and clamping his legs around him in a thinly veiled threat to break his spine if he didn't fuck him hard enough to forget this entire night ever happened.

Gintoki eagerly pulled him closer, grabbing and spreading his cheeks with both hands as he slotted his clothed dick between them. Shinsuke could feel how hard Gintoki was through his pants, and immediately grinded his hips down, enjoying the size and shape of him rubbing up against his twitching asshole.

"Where is the goddamn lube?" Shinsuke half-demanded, half-moaned into Gintoki's mouth as they continued to suck and bite at each other's lips.

"Under the bear," Gintoki panted.

"Ugh, I should've known it'd be under that fucking bear," Shinsuke cursed, breaking away to crawl towards the stuffed creature and fumble beneath its bum for the bottle of lube. _Damn, where was it?_ He dropped onto his elbows and felt a slight tug as what was left of his yukata started to tear. He'd long since accepted the fact that half of his wardrobe would surely become unsalvageable due to Gintoki's perverted antics. He shrugged it off his shoulders and turned back to find Gintoki sitting there like a useless lump, still fully clothed and with a small stream of blood now trickling out of his nose.

Shinsuke's entire face flushed as he realised the position he was in.

"Well, don't just sit there!" he snapped.

"Oh, yes. Right," Gintoki stuttered, hastily stripping off his kimono and wiping the blood on his sleeve.

Shinsuke rolled his eye, continuing to grope for the lube. "Why is this creepy thing even here? Why are there so _many_ of them?"

"Well, Zura told me that I should try to be more romantic or you would leave me for a younger man. Or a taller one. Or maybe even a woman! Not that I think anyone would have you anyway, I just thought it might be fun to try and recreate one of our favourite memories from the war—"

"You're assuming a lot, thinking any of my favourite memories involve you—"

"Oh, it wasn't just me. Our horses were there. Oh, and the rabbits. A mother fox and her family. Possibly also an owl—"

No.

Oh, no.

Oh, _hell_ no.

He quickly grasped the lube and wriggled it out from beneath the bear's soiled rump, his eye wide and darting towards the other stuffed animals with a dawning sense of horror.

"That's why I didn't bring any booze by the way," Gintoki ploughed on. "Mostly because Tatsuma promised to bring some of that good Amanto shit later, but listening to you beg sober is _so_ much more fun. I still dream about it sometimes, you know, how you begged me to stop and then begged me _not_ to stop, and how I _ravished_ you, right in front of all those cute, fluffy little bunnies—"

"REALLY, GINTOKI?" Shinsuke bellowed at him, completely uncaring of the fact that they were now both on their feet, stark naked. With their bodies smothered in dick cake. In the woods. At night. In front of an entire audience of stuffed animals. _"REALLY?"_

"Well, it was either this or that time we went behind the stables and I had to cover your mouth with my hand so the stable boy wouldn't hear us… Oh, or the cave! With the waterfall! All those cute little noises you made, they echoed so nicely… _Oh,_ or maybe that time we fucked on Zura's futon because he wouldn't shut up about—"

 _"You_ shut up!" Shinsuke exploded, his face so heated he could probably grill yakiniku on it. He took several deep breaths and heaved, wondering if it was too late to go back to being a terrorist and destroy Gintoki.

Who was, of course, still hard.

Shinsuke let out a long-suffering sigh. "Can you _please_ just shut up and fuck me already before I completely lose my mind?"

"I thought that was kind of the point," Gintoki grinned, and _oh,_ how he hated this particular grin—how it crinkled the corners of his mouth at a lopsided angle, dimpled his cheeks, and widened his eyes with childish glee—because even after all these years, he still found it so damn charming.

He leapt up onto the tip of his toes and threw his arms around Gintoki's neck, yanking him down in a furious attempt to kiss that stupid smile off his face. Gintoki only smiled harder, reaching behind Shinsuke's back and playfully smacking his ass.

Shinsuke gasped and tugged Gintoki's bottom lip into his mouth, giving it a sharp bite. "Quit messing around."

Gintoki chuckled. "I can't help it. You're so cute. Gin-san can only endure so much— _ow,_ fine! Aren't you going to at least suck me off first? Everyone knows you have to blow the candle or your wish won't come true. I drank nothing but Yakult for the past 24 hours just for you—"

"I fucking knew it!" Shinsuke growled, viciously squirting lube onto his hand and seizing Gintoki's cock with slightly more force than necessary. "I _knew_ you were the one who stole my Yakult! I didn't have any left to drink yesterday because of you—"

"I think the term you're looking for is 'borrowed,' because technically, you're about to—ah, _yes_ _!—_ swallow it all back in again."

"In what universe does your food go straight to your dick?" Shinsuke spat, his hand sliding up and down said dick with slick, wrenching twists that caused Gintoki's hips to buck up helplessly into the tight ring of his fingers. "Get down on your knees," Shinsuke commanded. "I want you to fuck me from behind so I don't have to look at your stupid face."

"Anything for you, princess," Gintoki rasped, giving him a wet, sloppy kiss on the corner of his mouth before roughly spinning him around and shoving him down onto his hands and knees.

He heard the pop of a bottle cap, followed by the squelch of lube being emptied onto Gintoki's hand, and his heart pounded in anticipation of the hard fucking he knew he was about to get. The fucking he had been _entitled to_ since this entire farce of a birthday began. He was not above begging at this point. He was irritated, impatient, and so damn _frustrated,_ if Gintoki didn't put something in him _now,_ he was going to slice off Gintoki's cock himself and use it as a dildo. Most days, he didn't even need the rest of him.

Gintoki startled him out of his silent tirade with a resounding slap to his ass. He smacked him again, harder, so hard the sharpness of it still rang in his ears and Shinsuke could still feel the sting of Gintoki's palm on his right cheek as the other man slid one finger into him. Shinsuke moaned and pushed back against him, trying to get him deeper.

"God, you're shameless," Gintoki whispered, holding his hips in place and cruelly withdrawing his finger, only to silence Shinsuke's whines of protest by shoving two fingers into him at once. Then, he scissored them apart, curling them down at an angle that sent Shinsuke sobbing down onto his elbows. "So loud," Gintoki continued, stroking in and out of him, his fingertips catching at all the right places. "Even with O'Beary Shun sitting right over there, watching us."

Wait. _What the fuck?_

"Gintoki," Shinsuke pleaded, his ass still throbbing and leaping back against Gintoki's hand for more despite himself. "Gintoki, please don't do this right now, you feel _so good—"_

"It's too late," Gintoki cackled sadistically, rubbing little circles around Shinsuke's prostate and dragging cry after helpless cry from him. "He already sees what a dirty slut you are."

"Gintoki," he wailed. "I swear to God, if you don't— _aaaahh_ —shut your mouth—"

"But if I do that, how will I eat you out, right in front of _all_ these wild animals?"

Shinsuke shoved back into him so hard, Gintoki stumbled over. He immediately scrambled on top before Gintoki could say another damn word, throwing all of his weight into his hips and impaling himself on Gintoki's cock.

 _This._ This was what made everything worth it. He threw back his head and let out a long, low moan at finally having Gintoki's entire length inside of him. His own cock gave a shuddering, dangerously pulsating throb at the sudden thickness searing up his backside. Gintoki was so _hard_ , the stretch was almost painful. He lifted his hips up to start riding him, causing Gintoki's cock to slip out ever so slightly and Shinsuke's hole to abruptly clench down in protest.

 _"Oh, fuck,"_ Gintoki groaned, watching his dick gradually slide out, despite the insistent tugging of Shinsuke's inner walls. The head of Gintoki's cock was now nudging right up against his prostate and he wasn't even trying to stifle the needy noises escaping from his lips. "Shit, you're killing me."

"I wish," Shinsuke mumbled drily, sinking back down with a wavering shout.

Shinsuke lifted himself back up again, his legs trembling from the way Gintoki's cock rubbed so smoothly against every groove and aching span of his insides. Gintoki slid his hands up his thighs, digging his fingers into his hips. Suddenly, he slammed him down, fucking into him so deep, Shinsuke's vision blacked out for one terrifying, thrilling instant.

 _"Uh,_ Gintoki, _yes_ _!"_ he cried out as Gintoki seized control of his hips and jerked him roughly up and down his length. Gintoki's eyes darkened into a deep crimson as their bodies slapped together faster and faster and Shinsuke's moans escalated in pitch. Gintoki had always enjoyed watching him fall to pieces while his dick was inside him. He wanted a show, and Shinsuke would give him one.

He began to touch himself as he rode him—a slight graze against his nipples, a lingering swipe of his tongue across his fingertips, a few quick, desperate strokes of his own dick. "Gintoki," he whimpered, biting his lower lip and looking straight into the eyes of the one person who was responsible for _everything._

Gintoki surged up, capturing Shinsuke's lips and his subsequent scream as the shift in position caused Gintoki's cock to glide in so deeply, he could barely keep moving. Gintoki's kisses were heated and messy, with just a bit of bite, but they were so dizzying, so passionate, so _them,_ Shinsuke lasted barely two more thrusts before his release exploded out of him and onto Gintoki's chest.

Gintoki didn't stop fucking him through his orgasm, forcing out every last drop until Shinsuke begged him to stop. He pushed Gintoki back down, slipping his still-erect cock out with a pained moan and turning himself around so that the red, puckered rim of his ass was now in Gintoki's face.

"Takasugi, what—"

"Shut up, I'm making my wish," he shushed him, leaning down and taking Gintoki's enormous dick into his mouth.

 _"Fucking shit!"_ Gintoki yelled, his hips jolting up and nearly causing Shinsuke to gag.

He desperately began to suck, running his tongue along the thick, angry-looking vein on the underside of Gintoki's cock and squeezing his lips together extra tight around the engorged head.

 _"Ah, yes,_ keep doing that," Gintoki grunted, grabbing his ass and swiping his tongue over Shinsuke's still-sensitive hole. Shinsuke whined around Gintoki's dick, the slick sensation tingling all the way up his spine. "Fuck, your ass tastes so good," Gintoki groaned between licks.

Shinsuke sucked harder, feeling lightheaded and heady from the constant penetration. His vision was starting to blur and his movements were becoming sloppy. At this rate, Gintoki's tongue was going to lick him through two more orgasms before he could taste Gintoki's cum.

He firmly shuffled his lower body out of Gintoki's reach, ignoring his groans of longing and turning himself back around so that Gintoki had an unimpeded view of him stretching his swollen lips around his cock.

"You're so filthy," Gintoki breathed, pulling on Shinsuke's hair and gently running his thumb over the closed lashes of Shinsuke's blind eye. "So desperate for me. Sucking my cock like that right after it's finished fucking your ass."

Saliva leaked out and trickled down Gintoki's length as Shinsuke whimpered impatiently, sliding Gintoki even deeper down his throat. He reached down, stroking Gintoki's balls and wrapping his hands around what he couldn't fit into his mouth. He started to increase his pace and the amount of suction, the weight of Gintoki on his tongue creating an immense ache inside him.

"Oh, shit," Gintoki gasped, tightening his grip on Shinsuke's head. "Oh, _fuck,_ I'm going to cum," he warned.

Shinsuke encouraged him, bending down with even louder, wetter suckling noises. His soft little mewls vibrated down Gintoki's thickening shaft as he held and squeezed him down his throat. The muscles in Gintoki's neck tensed as he arched up and yelled out his pleasure, flooding Shinsuke's mouth with hot streams of cum. Shinsuke swallowed frantically, unable to prevent some of it from spilling down the sides of his mouth and dripping a burning path down his chin.

He supposed it did taste a bit like Yakult.

He smirked around Gintoki's cock, then realised that he had forgotten to make an actual wish. He looked up at Gintoki's shaky grin as he reached down to brush a few sweaty strands of hair off Shinsuke's face, and he decided it didn't matter. He continued to pump Gintoki for more, only to choke on a last-minute spurt as an enraged screech burst out behind them.

"GIN-CHAN, YOU LIAR! I KNEW YOU WERE EATING CAKE WITHOUT ME!"

"SHIT, SHIT, SHIT, _SHIT,"_ Gintoki cursed, hastily tossing his kimono over Shinsuke, who was still coughing up gooey blobs of semen that had gotten lodged inside his windpipe. "Kagura-chan!" he called out to his savage Yato child in an unnaturally high-pitched voice. "Children your age should be in bed!"

"Adults your age should also be in bed," came the familiar, deadpan voice of the police officer who had almost arrested them during their last "incident" at the cherry blossom viewing.

 _"You!_ What are you doing out here with _him?"_ Gintoki shouted at his adopted daughter.

"We were going to join your party, but your party sucks. There's not even any food to eat. Only gross old men eating each other. Disgusting. I'd rather eat sukonbu," she declared, turning her nose up and marching away with the Shinsengumi boy in tow. He had his eye mask on, but still managed to smirk quite clearly in their direction before allowing himself to be led away from Gintoki's bellowing, empty threats.

"Well, that could've been worse," Gintoki said, scratching his head as he crouched back down beside Shinsuke. "So what now? We could go home and sleep. Or look for a cave. Or a sparkling waterfall. Or something."

"Surprise me," Shinsuke replied with a faint smile, bundling himself up in Gintoki's kimono and daring him to do his worst.

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THE END

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 **AUTHOR'S NOTE (2):**

 **If you made it this far, you are a brave soul indeed.**

 **Happy birthday, Shinsuke-sama! And Happy Exhibition Day from Australia! I'm sorry for dishonouring you. But the dark beast inside you has now been tranquillised by Gin-san's dick, so you're welcome.**

 **I'm rinrinsamurai on Tumblr/Twitter, if anyone wants to visit me in Hell :)**


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